Folding compartmented file

ABSTRACT

A three compartment file folded from a single blank. The blank, and file folded therefrom, includes a plurality of panels and flaps, along with foldlines and expanding folds. The assembled file incorporates an expanding closure flap to overlie the three compartments and a locking flap to lock the closure flap closed.

United States Patent Deckys Feb. 22, 1972 [54] FOLDING COMPARTMENTEDFILE [72] Inventor: Jonas Deckys, 19155 66th Pl. N.E., Seattle, Wash.98155 [22] Filed: Mar. 11, 1970 [21] Appl. No.: 18,557

[52] US. Cl ..229/72, 229/75, 229/76 [58] Field of Search ..229/72, 75,DIG. 3, DIG. 4, 229/76; 150/30, 32, 1.6

[56] References Cited UNITED STATES PATENTS 1,131,135 3/1915 Hudson..229/72X 3,414,185 12/1968 Young ..229/75 1,552,642 9/1925 Parks....229/75 X 3,180,555 4/1965 Barrett ..229/41 A Primary Examiner-JosephR. Leclair Assistant ExaminerStephen P. Garbe Att0rney-Clarence A.O'Brien and Harvey B. Jacobson 1 1 ABSTRACT A three compartment filefolded from a single blank. The blank, and file folded therefrom,includes a plurality of panels and flaps, along with foldlines andexpanding folds. The assembled file incorporates an expanding closureflap to overlie the three compartments and a locking flap to lock theclosure flap closed.

10 Claims, 7 Drawing Figures PATENTED FEB 2 2 I972 SHEET 1 0F 3 r ZOJonas Deckys I N VIZ N TOR 9mm WWW Em PATENTEDFEB22 I972 3.643 858 SHEET3 OF 3 V Jonas Deckys IN VIJNTOR.

FOLDING COMPARTMENTED FILE The instant invention is generally concernedwith a compartmented file, and more particularly relates to a uniquelyformed three compartment file constructed from a single specificallyconfigured and foldable blank.

Various objects of the instant invention reside in the provision of athree compartment file incorporating positive lock means, in the natureof interlocking cover and lock flaps, separate and easily accessibleexpanding compartments, and a configuration enabling an economicalconstruction of the file from a one-piece blank, preferably of alightweight cardboard or like material.

Further objects of the invention reside in the provision of acompartmented portable file which is inexpensive and easily constructed,requiring no elaborate machinery and utilizing only four preapplied glueareas, the file, notwithstanding the inexpensive and easily formednature thereof, being of a relatively durable, long lasting naturecapable of quite adequately protecting materials filed or storedtherein.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

FIG. 1 is a perspective view of the file of the instant invention in anopened position for the reception of material;

FIG. 2 is a perspective view of the file as the flaps are being closedthereon;

FIG. 3 is a perspective view of the closed file;

FIG. 4 is an enlarged cross-sectional view taken substantially on aplane passing along line 4-4 in FIG. 3;

FIG. 5 is another view of the closed file wherein the file has beenexpanded, through the expansible folds, for the accommodation ofasubstantial amount of material;

FIG. 6 is a top plan view of an open file spread so as to more clearlybring forth the construction detail thereof; and

FIG. 7 is a plan view of the flat one piece blank from which the file isformed.

Referring now more specifically to the drawings, reference numeral 10 isused to designate the file comprising the instant invention. The file l0incorporates three separate storage compartments l2, l4 and 16 and isconstructed from a onepiece flat blank 18, normally ofa cardboardmaterial.

Noting both the assembled file 10 and the blank 18 from which it isformed, it will be seen that the construction involved includes equalsize rectangular front and rear panels 20 and 22 interconnected by adouble central fold 24 defined by three parallel fold lines 26, thisdouble center fold 24 constituting the bottom of the file 10.

Located laterally of the combined center fold separated front and backpanels 20 and 22 are a pair of side panels 28, each integrally formedwith the adjacent front and back panels 20 and 22 and separatedtherefrom by a single fold defined by spaced parallel fold lines 32. Aswill be noted, the side panels 28 extend substantially the full combinedlength of the panels 20 and 22. Each side panel 28 includes a centrallylocated transverse double fold 34, defined by three fold lines 36,forming a relatively narrower continuation of the double center fold 24and being separated therefrom by a slit 38 formed in the adjoining foldline 32 at the point of intersection between the side panel fold 36 andthe side panel separating fold 30. Each side panel 28 additionallyincludes a pair of diagonal fold lines 40 extending from the outercorners 42 thereof inwardly to the opposed ends of the centrally locatedslit 38, the fold lines 36 and 40 dividing each side panel 28 into twocentral generally triangular sections 44 and two end generallytriangular sections 46.

Each side panel 28 is, in the file 10, extended substantiallyperpendicularly from the bottom forming double center fold 24 with thediagonal fold lines 40 folded inwardly so as to position the inner facesof the center sections 44 in facing relation and the outer face of eachcenter section 44 in facing relation to the outer face of the adjoiningouter section 46. Upon a folding of the side panels 28 in this manner,it will be appreciated that the front and back panels 20 and 22 are alsoupwardly folded above the double center fold 24.

Each side panel 28 is of a depth whereby, upon being folded in the abovedescribed manner, the angled portion defined adjacent each of the outercorners 42 overlaps, to a considerable degree, the corresponding portionon the opposite panel 28. This overlapped relationship will possibly bebest appreciated from FIG. 6. These overlapped portions are thenadhesively affixed to each other so as to retain the folded blank 18 inthe file forming configuration. Noting FIGS. 6 and 7, it will be seenthat the adhesively secured areas consist of the outer corner portionsof the two outer sections 46 on one side panel 28 and the outer cornerportions of the two center sections 44 on the other side panel 28, whichportions constitute the overlapped portions as indicated in FIG. 6.Reference numeral 48 generally designates the adhesive areas and, ifdeemed desirable, the adhesive can be preapplied to the blank 18 andinclude a covering of release paper or be of such a nature as to onlyadhere to like areas.

When assembled in this manner, it will be appreciated that the innerfaces of the aligned opposed side panel outer sec tions 46 form the twoend compartments 12 and 16, while the inner faces of the aligned opposedside panel center sections 44 define the enlarged central compartment14. The folds 30, which generally parallel the double center folds 34 inthe formed file 10, allow, in conjunction with the double center folds34, a selective expansion of the several compartments, the movement ofthe double center folds 34 being accommodated by the transverse slits 38provided between the side panel double folds 34 and the bottom formingdouble fold 24. The expansion of the various compartments also of courseresults in an expansion of the bottom forming center double fold 24whereby an adjustment in the internal carrying capacity of the file 10can be effected.

Referring now to FIG. 1, it will be noted that the compartment definingpartitions or walls, formed from the folded and overlapped side panelsections, each includes an elongated central recess 50 therein forfacilitating a grasping and removal of papers or the like from theindividual compartments. These recesses 50 are formed by inwardlyoffsetting the peripheral edges of each side panel 28 adjacent each ofthe outer corners 42 as indicated by reference numeral 52 with theserecessed or inwardly offset edge portions defining, in the folded file,the centrally located recess 50, while the unrecessed portions of theperipheral side panel edges define the upper edges of the compartmentdefining partition walls. In order to provide for a proper alignment ofthe recesses 50, it will be noted that the unrecessed side peripheraledge portions of each side panel 28 are each of a length approximatelyonehalf that of the unrecessed outer edge portion of the side panel 28.

The closing and locking of the file 10 is effected by means ofcooperating cover and lock flaps or panels 54 and 56 respectivelyintegrally engaged with and extending outwardly from the front and backpanels 20 and 22. Both of these flaps 54 and 56 extend along the fulllength of the respective sides of the panels 20 and 22. The cover flap54 is provided with an expanding double fold 58 immediately adjacent thefront panel 20 defined by three fold lines 60. In addition, the coverflap 54 is provided with a centrally located full length fold line 62which divides the flap 54 into an inner section 64 and an outer section66.

Noting FIGS. 2 and 4 in particular, the cover flap 54 is folded aboutthe fold line 62 so as to generally overlie the sections 66 and 64 anddefine an upwardly or outwardly directed elongated pocket 68. Thispocket 68 is inserted in the rearmost compartment 12, the cover flap 54selectively folding about the fold lines 60 in accordance with theparticular thickness of the file 10, which allow for a selectiveexpansion of the cover flap 54 so as to accommodate the variations inthe thickness of the file 10. It is contemplated that the opposed endedges of the flap 54 be centrally relieved adjacent the opposed ends ofthe fold line 62 so as to provide for a slightly reduced length to theflap 54 along the lower edge of the pocket 68, such being the edgeinitially introduced in the rear compartment 12. In this manner, thecover flap can easily be inserted into the rearmost pocket. In addition,to accommodate the folding of the cover flap, it will be noted thatsmall recesses or notches 70 are provided at the inner corners definedbetween the end edges of the cover flap 54 and the adjoining side edgesof the side panels 28.

The outer section 66 of the cover flap 54, being ofa greater width thanthe inner section 64, projects slightly above the top edges of thecompartment dividing partitions and lies against or is adapted to lieagainst the inner unfolded section 72 of the lock flap 56 which forms asmooth unfolded continuation of the back panel 22 Outwardly of the innersection 72, the lock flap 56 includes both a central section 74 and anouter section 76, defined by a pair of laterally spaced full length foldlines 78. Both of the sections 74 and 76 are adapted to fold about theinner fold line 78 and be received within the seated pocket 68 so as tocover the outer section 66 of the cover flap 54 and prevent an outwarddrawing of the section forming pocket 68 from the back compartment untila prior removal of the lock flap sections 74 and 76. The outer fold line78 functions primarily as a means for facilitating the inward turning orfolding of the lock flap into engagement within the cover flap pocket68. Finally, it will be noted that a centrally located tab 80 isintegrally formed with the outer lock flap section 76 and is inwardlydirected, being cut from the adjacent center section 74. This tab 80,upon a folding of the lock flap sections 74 and 76 about the inner foldline 78 so as to be received within the cover flap pocket 68, projectsupwardly out of the pocket and provides a conveniently grasping meansfor withdrawing the pocket received lock flap sections. it iscontemplated that the central lock flap section 74 be of a width so asto position the outer fold line 78, and hence the secured end of the tab80, at substantially the level of the upper edge of the compartmentdividing partition walls.

From the foregoing, it will be appreciated that a highly uniquecompartmental file defining construction has been set forth wherein asingle specifically configured blank is selectively foldable so as toproduce an adhesively secured file incorporating three compartments andcomplementary cover and lock flaps therefor. The file, upon beingassembled from the blank, is selectively expandable and contractable soas to conform to the thickness of the contents and provide a compactcontainer for such contents. The actual interlocking of the varioussections or portions of the blank so as to define the compartmented fileinvolves, in addition to the basic folding of the blank, only theapplication of adhesive or the like securing means at two points, thetwo points of overlap between the sections of the opposed side panels.lncidently, in order to provide for a substantially equal height betweenthe front and back panels and the intermediate partitions, the lateralheight of the side panels 28 is equal to that of the front and rearpanels and 22.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

What is claimed as new is as follows:

1. A compartmented file defining construction comprising front and backrectangular panels having outer edges, adjacent inner edges, and alignedside edges, a foldable interconnection along and between the adjacentinner edges of the front and back panels, a pair of side panels havinginner and outer edges and opposed side edges, edge fold means foldablyconnecting the inner edges of the side panels to the opposed alignedside edges of the front and back panels, each side panel havingtransverse fold means thereacross between the inner and outer edgesthereof in alignment with the foldable interconnection between the frontand back panels, each side panel having a pair of outer corners anddiagonal fold means extending from said corners to approximately theinner edge end of the transverse fold means for forming two central sidepanel sections to the opposite sides of the transverse fold means andtwo outer side panel sections outward of the diagonal fold means, eachside panel outer section and the adjoining central section beinginwardly foldable as a unit between the adjacent front and back panelsand the transverse fold means, means engageable between the opposed sidesection and central section units on the opposite side panels to formpartition walls and divide the space between the front and back panelsinto three compartments, the foldable interconnection between the frontand back panels, the edge fold means, and the transverse fold meansbeing in the nature of expandible folds, each defined by a plurality oflaterally spaced fold lines, a cover flap integrally formed with andalong the outer edge of the front panel and projecting outwardlytherefrom, said cover flap having an expansible fold defined therealongadjacent the outer edge of said front panel, and a longitudinal foldline defined along said cover flap between the cover flap expansiblefold and the outer edge of the cover flap for enabling a folding of thecover flap in a manner so as to define an upwardly opening pocketreceivable within the formed compartment adjacent the back panel withthe cover flap overlying the remaining two compartments.

2. The construction of claim 1, including a lock flap integrally formedwith and along the outer edge of the back panel and projecting outwardlytherefrom, said lock flap having a fold line defined longitudinallythereacross so as to define an outer lock flap section inwardly foldableabout the lock flap fold line, said lock flap outer section beingreceivable within the upwardly opening pocket defined by the compartmentreceivable folded cover flap for a locking of the folded cover flapwithin the corresponding compartment.

3. The construction of claim 2, wherein the side and outer edges of theside panels combine to form the upper edges along the partition walls,each side edge of each side panel combining with approximately one-halfof the outer edge of the corresponding panel to define approximatelyone-half of the upper edge ofone of the partition walls.

4. The construction of claim 3, wherein the side panel side and outeredges, adjacent each outer corner, are inwardly offset for approximatelythe same length, these inwardly offset edge portions defining centralrecesses in the formed partition walls.

5. The construction of claim 4, wherein the outer section of the lockflap includes an integral centrally located gripping tab projecting fromthe lock flap fold line away from the lock flap outer section.

6. A compartmented file defining construction comprising front and backrectangular panels having outer edges, adjacent inner edges, and alignedside edges, a foldable interconnection along and between the adjacentinner edges of the front and back panels, a pair of side panels havinginner and outer edges and opposed side edges, edge fold means foldablyconnecting the inner edges of the side panels to the opposed alignedside edges of the front and back panels, each side panel havingtransverse fold means thereacross between the inner and outer edgesthereof in alignment with the foldable interconnection between the frontand back panels, each side panel having a pair of outer corners anddiagonal fold means extending from said corners to approximately theinner edge end of the transverse fold means for forming two central sidepanel sections to the opposite sides of the transverse fold means andtwo outer side panel sections outward of the diagonal fold means, eachside panel outer section and the adjoining central section beinginwardly foldable as a unit between the adjacent front and back panelsand the transverse fold means, means engageable between the opposed sidesection and central section units on the opposite side panels to formpartition walls and divide the space between the front and back panelsinto three compartments, the side and outer edges of the side panelscombining to form the upper edges along the partition walls, each sideedge of each side panel combining with approximately one-half of theouter edge of the corresponding panel to define approximately one-halfof the upper edge of one of the partition walls, the side panel, sideand outer edges, adjacent each outer corner, being inwardly offset forapproximately the same length, these inwardly offset edge portionsdefining central recesses in the formed partition walls.

7. A compartmented file defining construction comprising front and backrectangular panels having outer edges, adjacent inner edges, and alignedside edges, a foldable interconnection along and between the adjacentinner edges of the front and back panels, a pair of side panels havinginner and outer edges and opposed side edges, edge fold means foldablyconnecting the inner edges of the side panels to the opposed alignedside edges of the front and back panels, each side panel havingtransverse fold mean thereacross between the inner and outer edgesthereof in alignment with the foldable interconnection between the frontand back panels, each side panel having a pair of outer corners anddiagonal fold means extending from said corners to approximately theinner edge end of the transverse fold means for forming two central sidepanel sections to the opposite sides of the transverse fold means andtwo outer side panel sections outward of the diagonal fold means, eachside panel outer section and the adjoining central section beinginwardly foldable as a unit between the adjacent front and back panelsand the transverse fold means, means engageable between the opposed sidesection and central section units on the opposite side panels to formpartition walls and divide the space between the front and back panelsinto three compartments, a cover flap integrally formed with and alongthe outer edge of the front panel and projecting outwardly therefrom,said cover flap having a fold defined therealong adjacent the outer edgeof said front panel, and a longitudinal fold line defined along saidcover flap between the cover flap fold and the outer edge of the coverflap for enabling a folding of the cover flap in a manner so as todefine an upwardly opening pocket receivable within the formedcompartment adjacent the back panel with the cover flap overlying theremaining two compartments, a lock flap integrally formed with and alongthe outer edge of the back panel and projecting outwardly therefrom,said lock flap having a fold line defined longitudinally thereacross soas to define an outer lock flap section inwardly foldable about the lockflap fold line, said lock flap outer section being receivable within theupwardly opening pocket defined by the compartment receivable foldedcover flap for a locking of the folded cover flap within thecorresponding compartment 8. The construction of claim 7, wherein theouter section of the lock flap includes an integral centrally locatedgripping tab projecting from the lock flap fold line away from the lockflap outer section.

9. A three compartment folding file formed from a single blank, saidfile comprising rectangular front and back panels integrally andfoldably connected along the lower edges thereof, a pair of side panelsintegrally and foldably interconnected with the opposed side edges ofthe front and back panels and extending therebetween, each side panelhaving two inwardly folded portions, the inwardly folded portions ofeach side panel engaging the corresponding inwardly folded portions ofthe other side panel between the front and back panels, and meansinterconnecting the engaged inwardly folded side panel portions so as todefine a pair of compartment defining partition walls, said partitionwalls defining, in conjunction with the front and back panels, threecompartments, a full length cover flap integral with the front panelalong the upper edge thereof, said cover flap being selectivelyextensible over the compartments and foldable into the compartmentimmediately adjacent the back panel, said cover flap defining, in thecompartment adjacent the back panel, an upwardly opening pocket, and alock fla integral with and along the upper edge of the back panel, sailock ap having a folda ble outer section selectively introducible intothe upwardly opening compartment received pocket defined by the coverflap for retention of the cover flap within the compartment.

10. A one-piece blank foldable into a three compartmented file, saidblank comprising a generally rectangular sheet, first fold meansextending transversely across said sheet and dividing said sheet intoapproximately two equal halves, second fold means extending across saidsheet transversely of the first fold means and at two laterally spacedpoints so as to define a central area and two side areas, each side areahaving a pair of outer corners, third fold means extending diagonallyfrom each outer corner inwardly to approximately the point ofintersection between the first fold means and the adjacent second foldmeans, said center area including opposed edges at right angles to saidside areas and in outwardly spaced parallel relation to said first foldmeans, and full length flaps secured to and projecting outwardly fromsaid center area opposed edges, each flap including fold meansthereacross parallel to said first fold means, each side area having apair of adhesive areas thereon adjacent the outer corners thereof, theadhesive areas on one side area being to one side of the third foldmeans, and on the other side area being to the other side of the thirdfold means, each side area including opposed side edges and an outeredge, said side area edges being inwardly offset adjacent the corners ofthe side areas.

1. A compartmented file defining construction comprising front and backrectangular panels having outer edges, adjacent inner edges, and alignedside edges, a foldable interconnection along and between the adjacentinner edges of the front and back panels, a pair of side panels havinginner and outer edges and opposed side edges, edge fold means foldablyconnecting the inner edges of the side panels to the opposed alignedside edges of the front and back panels, each side panel havingtransverse fold means thereacross between the inner and outer edgesthereof in alignment with the foldable interconnection between the frontand back panels, each side panel having a pair of outer corners anddiagonal fold means extending from said corners to approximately theinner edge end of the transverse fold means for forming two central sidepanel sections to the opposite sides of the transverse fold means andtwo outer side panel sections outward of the diagonal fold means, eachside panel outer section and the adjoining central section beinginwardly foldable as a unit between the adjacent front and back panelsand the transverse fold means, means engageable between the opposed sidesection and central section units on the opposite side panels to formpartition walls and divide the space between the front and back panelsinto three compartments, the foldable interconnection between the frontand back panels, the edge fold means, and the transverse fold meansbeing in the nature of expandible folds, each defined by a plurality oflaterally spaced fold lines, a cover flap integrally formed with andalong the outer edge of the front panel and projecting outwardlytherefrom, said cover flap having an expansible fold defined therealongadjacent the outer edge of said front panel, and a longitudinal foldline defined along said cover flap between the cover flap expansiblefold and the outer edge of the cover flap for enabling a folding of thecover flap in a manner so as to define an upwardly opening pocketreceivable within the formed compartment adjacent the back panel withthe cover flap overlying the remaining two compartments.
 2. Theconstruction of claim 1, including a lock flap integrally formed withand along the outer edge of the back panel and projecting outwardlytherefrom, said lock flap having a fold line defined longitudinallythereacross so as to define an outer lock flap section inwardly foldableabout the lock flap fold line, said lock flap outer section beingreceivable within the upwardly opening pocket defined by the compartmentreceivable folded cover flap for a locking of the folded cover flapwithin the corresponding compartment.
 3. The construction of claim 2,wherein the side and outer edges of the side panels combine to form theupper edges along the partition walls, each side edge of each side panelcombining with approximately one-half of the outer edge of thecorResponding panel to define approximately one-half of the upper edgeof one of the partition walls.
 4. The construction of claim 3, whereinthe side panel side and outer edges, adjacent each outer corner, areinwardly offset for approximately the same length, these inwardly offsetedge portions defining central recesses in the formed partition walls.5. The construction of claim 4, wherein the outer section of the lockflap includes an integral centrally located gripping tab projecting fromthe lock flap fold line away from the lock flap outer section.
 6. Acompartmented file defining construction comprising front and backrectangular panels having outer edges, adjacent inner edges, and alignedside edges, a foldable interconnection along and between the adjacentinner edges of the front and back panels, a pair of side panels havinginner and outer edges and opposed side edges, edge fold means foldablyconnecting the inner edges of the side panels to the opposed alignedside edges of the front and back panels, each side panel havingtransverse fold means thereacross between the inner and outer edgesthereof in alignment with the foldable interconnection between the frontand back panels, each side panel having a pair of outer corners anddiagonal fold means extending from said corners to approximately theinner edge end of the transverse fold means for forming two central sidepanel sections to the opposite sides of the transverse fold means andtwo outer side panel sections outward of the diagonal fold means, eachside panel outer section and the adjoining central section beinginwardly foldable as a unit between the adjacent front and back panelsand the transverse fold means, means engageable between the opposed sidesection and central section units on the opposite side panels to formpartition walls and divide the space between the front and back panelsinto three compartments, the side and outer edges of the side panelscombining to form the upper edges along the partition walls, each sideedge of each side panel combining with approximately one-half of theouter edge of the corresponding panel to define approximately one-halfof the upper edge of one of the partition walls, the side panel, sideand outer edges, adjacent each outer corner, being inwardly offset forapproximately the same length, these inwardly offset edge portionsdefining central recesses in the formed partition walls.
 7. Acompartmented file defining construction comprising front and backrectangular panels having outer edges, adjacent inner edges, and alignedside edges, a foldable interconnection along and between the adjacentinner edges of the front and back panels, a pair of side panels havinginner and outer edges and opposed side edges, edge fold means foldablyconnecting the inner edges of the side panels to the opposed alignedside edges of the front and back panels, each side panel havingtransverse fold mean thereacross between the inner and outer edgesthereof in alignment with the foldable interconnection between the frontand back panels, each side panel having a pair of outer corners anddiagonal fold means extending from said corners to approximately theinner edge end of the transverse fold means for forming two central sidepanel sections to the opposite sides of the transverse fold means andtwo outer side panel sections outward of the diagonal fold means, eachside panel outer section and the adjoining central section beinginwardly foldable as a unit between the adjacent front and back panelsand the transverse fold means, means engageable between the opposed sidesection and central section units on the opposite side panels to formpartition walls and divide the space between the front and back panelsinto three compartments, a cover flap integrally formed with and alongthe outer edge of the front panel and projecting outwardly therefrom,said cover flap having a fold defined therealong adjacent the outer edgeof said front panel, and a longitudinal fold line Defined along saidcover flap between the cover flap fold and the outer edge of the coverflap for enabling a folding of the cover flap in a manner so as todefine an upwardly opening pocket receivable within the formedcompartment adjacent the back panel with the cover flap overlying theremaining two compartments, a lock flap integrally formed with and alongthe outer edge of the back panel and projecting outwardly therefrom,said lock flap having a fold line defined longitudinally thereacross soas to define an outer lock flap section inwardly foldable about the lockflap fold line, said lock flap outer section being receivable within theupwardly opening pocket defined by the compartment receivable foldedcover flap for a locking of the folded cover flap within thecorresponding compartment.
 8. The construction of claim 7, wherein theouter section of the lock flap includes an integral centrally locatedgripping tab projecting from the lock flap fold line away from the lockflap outer section.
 9. A three compartment folding file formed from asingle blank, said file comprising rectangular front and back panelsintegrally and foldably connected along the lower edges thereof, a pairof side panels integrally and foldably interconnected with the opposedside edges of the front and back panels and extending therebetween, eachside panel having two inwardly folded portions, the inwardly foldedportions of each side panel engaging the corresponding inwardly foldedportions of the other side panel between the front and back panels, andmeans interconnecting the engaged inwardly folded side panel portions soas to define a pair of compartment defining partition walls, saidpartition walls defining, in conjunction with the front and back panels,three compartments, a full length cover flap integral with the frontpanel along the upper edge thereof, said cover flap being selectivelyextensible over the compartments and foldable into the compartmentimmediately adjacent the back panel, said cover flap defining, in thecompartment adjacent the back panel, an upwardly opening pocket, and alock flap integral with and along the upper edge of the back panel, saidlock flap having a foldable outer section selectively introducible intothe upwardly opening compartment received pocket defined by the coverflap for retention of the cover flap within the compartment.
 10. Aone-piece blank foldable into a three compartmented file, said blankcomprising a generally rectangular sheet, first fold means extendingtransversely across said sheet and dividing said sheet intoapproximately two equal halves, second fold means extending across saidsheet transversely of the first fold means and at two laterally spacedpoints so as to define a central area and two side areas, each side areahaving a pair of outer corners, third fold means extending diagonallyfrom each outer corner inwardly to approximately the point ofintersection between the first fold means and the adjacent second foldmeans, said center area including opposed edges at right angles to saidside areas and in outwardly spaced parallel relation to said first foldmeans, and full length flaps secured to and projecting outwardly fromsaid center area opposed edges, each flap including fold meansthereacross parallel to said first fold means, each side area having apair of adhesive areas thereon adjacent the outer corners thereof, theadhesive areas on one side area being to one side of the third foldmeans, and on the other side area being to the other side of the thirdfold means, each side area including opposed side edges and an outeredge, said side area edges being inwardly offset adjacent the corners ofthe side areas.